Excel Automation: Protect single worksheet from deletion by user.

Question

VSTO 4.0 / Office 2007

In an Excel document-level automation project, I have a worksheet that must not be deleted from the workbook. I am afraid that a careless user might delete it by accident, which currently causes a lot of grief (exceptions galore).

I can not protect the entire workbook, because the user must be able to create, delete and otherwise modify this file. Exactly one sheet needs to be protected from deletion, but I may be overlooking something, so if there exists such solution I'm all ears. For example I could imagine that I can Protect() and Unprotect() the workbook when the sheet is visible, but this solution seems messy.

Googling yielded the following VBA code:

Private Sub Worksheet_Activate()
Dim CB As CommandBar
Dim Ctrl As CommandBarControl
For Each CB In Application.CommandBars
Set Ctrl = CB.FindControl(ID:=847, recursive:=True)
If Not Ctrl Is Nothing Then
Ctrl.OnAction = "RefuseToDelete"
Ctrl.State = msoButtonUp
End If
Next
End Sub

I'm not familiar with VBA, but I tried running this from the VSTO generated startup method:

private void Sheet1_Startup(object sender, System.EventArgs e)
{
    //Is there a neater way to iterate through all Office Collections?
    for (var i = 1; i <= Application.CommandBars.Count; i++)
    {
        var commandBar = Application.CommandBars[i];
        //847 is a magical constant that any fule no has something to do with sheet deletion
        var control = commandBar.FindControl(Id: 847, Recursive: true);
        if (control != null) control.OnAction = null;
    }
}

This code seems to do exactly nothing. You may ask "Hey, Gleno, why are you setting OnAction to null" , well I don't know what to set it to... The linked VBA solution attaches to Activate and Deactivate events, so there's more code where that came from.

Thanks in advance.